My Child & I: Vaccination – Part II

In Part I of this series, we discussed the basic workings of vaccines. Here we will talk about the different types of vaccines available and how this affects your child. Don’t forget to read Parts III & IV for more information.

Part II: Vaccine types & series

As we have mentioned in Part I of the series, vaccines are medical products given to immunise the body against specific diseases. This is to prevent serious, often life-threatening complications that may accompany certain infections. A tribute to the success of the vaccine is the story of polio. Once a serious cause of disability and death all across the world, polio today has been almost completely wiped off the face of the earth. Here we will discuss further regarding vaccination series and boosters, as well learn a little more about the different types of vaccines available.

What are the different vaccine types?

Vaccines can be divided into a number of different groups. Classically, the commonest division is live vaccines versus inactivated vaccines.

Live vaccines contain living infectious agents which are used to trigger the body’s immune response . These living agents are however either grown or modified such that while they retain the capability to trigger an immune response, they are unable to cause the detrimental effects of the wild type infectious agent. Examples of live vaccines are the MMR (Measles, Mumps, Rubella) and Varicella (Chickenpox) vaccines.

Inactivated vaccines on the other hand are composed of particles harvested from dead or inactivated infectious agents. These particles possess the necessary qualities to trigger the body’s immune response, but again are incapable of causing harm by themselves. Examples of inactivated vaccines would be the Hepatitis B and the DPT (Diptheria, Pertussis, Tetanus) vaccines.

Vaccines can also be grouped into single or combined vaccines. Single vaccines generally provide immunity against a single infectious agent, while combined vaccines have confer protection against two or more infectious agents in a single dose. Examples of single vaccines would be the Hepatitis B vaccine or the chickenpox vaccine, while the DPT and MMR vaccines are examples of combined vaccines.

One last categorization of vaccines is the route of administration. Traditionally most vaccines are injected; for example all of the vaccines listed above. Some vaccines however, can be deliver orally or intranasally. The OPV ( Oral Polio Virus) and Rotavirus vaccine come as oral drops for example, while there has been recent use of intranasal drops to vaccinate against Influenza in countries such as America.

How do the different groups affect my child?

No one likes to get an injection, least of all children. Oral and nasal vaccines minimize the need for needle use and are much easier to administer. However, non-injectable vaccines are still few and far between. The oral route has long been eschewed as the powerful digestive system often breaks up the vaccine before it can enter the body and trigger the appropriate immune response. There have been promising developments with intranasal vaccinations, but as studies have yet to show they are as effective (or safe!) as the standard injectable vaccines, they are still viewed as somewhat experimental.

An alternative way to reduce the number of shots taken is to use combined vaccines rather than single vaccines. There’s been good progress in this aspect and vaccines nowadays may combine up to 6 different components to protect against as many diseases. However, the chances of developing side effects such as fever or flu-like symptoms tends to increase with the number of vaccines concurrently given, so that is one trade-off that has to be considered.

One other way many parents (and doctors!) tend to minimize the number of vaccination visits required is by scheduling and giving multiple vaccines at the same time. Very often, the concerned parent gets confused as to why certain vaccines can be given together and why they have to wait between others. This usually depends on whether the child is being administered a live or inactivated vaccine.

Generally, inactivated vaccines can be safely administered with one another or shortly thereafter. While live vaccines can similarly (and safely) be given together with inactivated ones, most experts agree that two different live vaccines should either be given on the same visit or, failing which, should be administered a minimum of 4 weeks apart from one another. It is also of note that the chances of side effects are much higher when live vaccines are given together.

Having this knowledge in hand, don’t forget to read the next part, where we will talk about vaccine series, boosters and their role in maintaining good health.